TULSA, Oklahoma - Police say criminals are using kiosks to sell what they steal, but the machines also make it easier for police to catch them.

A company called ecoATM has two buy-back kiosks in Tulsa, one at Woodland Hills Mall and one at Promenade. They are automated machines that pay money for cell phones and tablets.

"Anything that has a cord hooked up to it and is portable, these places will take," said Detective J.W. Sherrill with Tulsa police.

Tulsa police get about 18,000 larceny cases a year with only 12 investigators to work them all. A third of those cases are stolen electronics, and if you figure an average price of $200, that's more than a million dollars in stolen gadgets a year in Tulsa.

They say there's big black market for electronics because the demand is so high, so criminals are always looking for ways to sell the stolen goods and some are using the kiosks as yet another way.

"We recover phones from all over, pawn shop, Craigslist, any place they're listed electronically and yes, we have recovered a bunch of them from ecoATM," Sherrill said.

When officers get a report, they run the serial number of the stolen item through several databases and ecoATM participates in those databases.

The company tries to make it as hard as possible for criminals to use the machines. They take a picture of the person selling the device, a picture of the person's driver's license and a picture of the device itself.

"They are very, very, very friendly to law enforcement. They want to help people get their property back," Sherrill said.

The problem is, about 70 percent of people don't have a clue what their serial number is or how to find it, which means there's not a lot officers can do to track it down and get it back to you.

The bottom line is, record the serial numbers of everything you like and want to keep track of, take a picture, download it someplace safe where you can access it later. If you don't, the chances of you seeing your stolen items again are pretty slim.

In a statement, ecoATM said:

“ecoATM is committed to establishing lasting and collaborative relations with our law enforcement associates. We have implemented extensive security features and processes to deter the sale of any stolen device. We also provide detailed information to law enforcement about each and every transaction, and in the rare case that a stolen phone does make its way into our kiosk, we also provide law enforcement with the information and evidence they need to prosecute the individual and return the stolen property to the victim, promptly upon request and without the need for a subpoena.”